/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.wiser.library.zxing.camera;

import java.io.IOException;

import android.content.Context;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Rect;
import android.hardware.Camera;
import android.os.Build;
import android.os.Handler;
import android.util.Log;
import android.view.SurfaceHolder;

import com.wiser.library.util.WISERApp;

/**
 * @author Wiser
 * @version 版本
 */
public final class CameraManager {

	private static final String		TAG					= CameraManager.class.getSimpleName();

	private static int				MIN_FRAME_WIDTH		= 520;

	private static int				MIN_FRAME_HEIGHT	= 520;

	private static int				MAX_FRAME_WIDTH		= 640;

	private static int				MAX_FRAME_HEIGHT	= 640;

	private static CameraManager	cameraManager;

	static final int				SDK_INT;													// Later we can use Build.VERSION.SDK_INT

	static {
		int sdkInt;
		try {
			sdkInt = Integer.parseInt(Build.VERSION.SDK);
		} catch (NumberFormatException nfe) {
			// Just to be safe
			sdkInt = 10000;
		}
		SDK_INT = sdkInt;
	}

	private final Context						context;

	private final CameraConfigurationManager	configManager;

	private Camera								camera;

	private Rect								framingRect;

	private Rect								framingRectInPreview;

	private boolean								initialized;

	private boolean								previewing;

	private final boolean						useOneShotPreviewCallback;

	/**
	 * Preview frames are delivered here, which we pass on to the registered
	 * handler. Make sure to clear the handler so it will only receive one message.
	 */
	private final PreviewCallback				previewCallback;

	/**
	 * Autofocus callbacks arrive here, and are dispatched to the Handler which
	 * requested them.
	 */
	private final AutoFocusCallback				autoFocusCallback;

	/**
	 * Initializes this static object with the Context of the calling Activity.
	 *
	 * @param context
	 *            The Activity which wants to use the camera.
	 */
	public static void init(Context context) {
		if (cameraManager == null) {
			cameraManager = new CameraManager(context);
		}
		setInitValueResolution();
	}

	// 计算分辨率设置初始值
	private static void setInitValueResolution() {
		int resolution = 0;
		if (WISERApp.getScreenDisplay().length > 0) {
			resolution = WISERApp.getScreenDisplay()[0];
		}
		if (resolution > 1080) {// 分辨率大于1080
			MIN_FRAME_WIDTH = 600;
			MIN_FRAME_HEIGHT = 600;
			MAX_FRAME_WIDTH = 720;
			MAX_FRAME_HEIGHT = 720;
		} else if (resolution <= 1080 && resolution > 720) {
			MIN_FRAME_WIDTH = 550;
			MIN_FRAME_HEIGHT = 550;
			MAX_FRAME_WIDTH = 670;
			MAX_FRAME_HEIGHT = 670;
		} else if (resolution > 540 && resolution <= 720) {// 分辨率小于1080
			MIN_FRAME_WIDTH = 400;
			MIN_FRAME_HEIGHT = 400;
			MAX_FRAME_WIDTH = 490;
			MAX_FRAME_HEIGHT = 490;
		} else if (resolution <= 540) {
			MIN_FRAME_WIDTH = 370;
			MIN_FRAME_HEIGHT = 370;
			MAX_FRAME_WIDTH = 460;
			MAX_FRAME_HEIGHT = 460;
		}
	}

	/**
	 * Gets the CameraManager singleton instance.
	 *
	 * @return A reference to the CameraManager singleton.
	 */
	public static CameraManager get() {
		return cameraManager;
	}

	private CameraManager(Context context) {

		this.context = context;
		this.configManager = new CameraConfigurationManager(context);

		// Camera.setOneShotPreviewCallback() has a race condition in Cupcake, so we use
		// the older
		// Camera.setPreviewCallback() on 1.5 and earlier. For Donut and later, we need
		// to use
		// the more efficient one shot callback, as the older one can swamp the system
		// and cause it
		// to run out of memory. We can't use SDK_INT because it was introduced in the
		// Donut SDK.
		// useOneShotPreviewCallback = Integer.parseInt(Build.VERSION.SDK) >
		// Build.VERSION_CODES.CUPCAKE;
		useOneShotPreviewCallback = Integer.parseInt(Build.VERSION.SDK) > 3; // 3 = Cupcake

		previewCallback = new PreviewCallback(configManager, useOneShotPreviewCallback);
		autoFocusCallback = new AutoFocusCallback();
	}

	public void flashHandler() {
		// camera.startPreview();
		if (camera != null) {
			Camera.Parameters parameters = camera.getParameters();
			// 判断闪光灯当前状态來修改
			if (Camera.Parameters.FLASH_MODE_OFF.equals(parameters.getFlashMode())) {
				turnOn(parameters);
			} else if (Camera.Parameters.FLASH_MODE_TORCH.equals(parameters.getFlashMode())) {
				turnOff(parameters);
			}
		}
	}

	// 開
	private void turnOn(Camera.Parameters parameters) {
		parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
		camera.setParameters(parameters);
	}

	// 關
	private void turnOff(Camera.Parameters parameters) {
		parameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
		camera.setParameters(parameters);
	}

	/**
	 * Opens the camera driver and initializes the hardware parameters.
	 *
	 * @param holder
	 *            The surface object which the camera will draw preview frames into.
	 * @throws IOException
	 *             Indicates the camera driver failed to open.
	 */
	public void openDriver(SurfaceHolder holder) throws IOException {
		if (camera == null) {
			camera = Camera.open();
			if (camera == null) {
				throw new IOException();
			}
			camera.setPreviewDisplay(holder);

			if (!initialized) {
				initialized = true;
				configManager.initFromCameraParameters(camera);
			}
			configManager.setDesiredCameraParameters(camera);

			// FIXME
			// SharedPreferences prefs =
			// PreferenceManager.getDefaultSharedPreferences(context);
			// 是否使用前灯
			// if (prefs.getBoolean(PreferencesActivity.KEY_FRONT_LIGHT, false)) {
			// FlashlightManager.enableFlashlight();
			// }
			FlashlightManager.enableFlashlight();
		}
	}

	/**
	 * Closes the camera driver if still in use.
	 */
	public void closeDriver() {
		if (camera != null) {
			FlashlightManager.disableFlashlight();
			camera.release();
			camera = null;
		}
	}

	/**
	 * Asks the camera hardware to begin drawing preview frames to the screen.
	 */
	public void startPreview() {
		if (camera != null && !previewing) {
			camera.startPreview();
			previewing = true;
		}
	}

	/**
	 * Tells the camera to stop drawing preview frames.
	 */
	public void stopPreview() {
		if (camera != null && previewing) {
			if (!useOneShotPreviewCallback) {
				camera.setPreviewCallback(null);
			}
			camera.stopPreview();
			previewCallback.setHandler(null, 0);
			autoFocusCallback.setHandler(null, 0);
			previewing = false;
		}
	}

	/**
	 * A single preview frame will be returned to the handler supplied. The data
	 * will arrive as byte[] in the message.obj field, with width and height encoded
	 * as message.arg1 and message.arg2, respectively.
	 *
	 * @param handler
	 *            The handler to send the message to.
	 * @param message
	 *            The what field of the message to be sent.
	 */
	public void requestPreviewFrame(Handler handler, int message) {
		if (camera != null && previewing) {
			previewCallback.setHandler(handler, message);
			if (useOneShotPreviewCallback) {
				camera.setOneShotPreviewCallback(previewCallback);
			} else {
				camera.setPreviewCallback(previewCallback);
			}
		}
	}

	/**
	 * Asks the camera hardware to perform an autofocus.
	 *
	 * @param handler
	 *            The Handler to notify when the autofocus completes.
	 * @param message
	 *            The message to deliver.
	 */
	public void requestAutoFocus(Handler handler, int message) {
		if (camera != null && previewing) {
			autoFocusCallback.setHandler(handler, message);
			// Log.d(TAG, "Requesting auto-focus callback");
			camera.autoFocus(autoFocusCallback);
		}
	}

	/**
	 * Calculates the framing rect which the UI should draw to show the user where
	 * to place the barcode. This target helps with alignment as well as forces the
	 * user to hold the device far enough away to ensure the image will be in focus.
	 *
	 * @return The rectangle to draw on screen in window coordinates.
	 */
	public Rect getFramingRect() {
		Point screenResolution = configManager.getScreenResolution();
		if (framingRect == null) {
			if (camera == null) {
				return null;
			}
			int width = screenResolution.x * 3 / 4;
			// int width = screenResolution.x;
			if (width < MIN_FRAME_WIDTH) {
				width = MIN_FRAME_WIDTH;
			} else if (width > MAX_FRAME_WIDTH) {
				width = MAX_FRAME_WIDTH;
			}
			int height = screenResolution.y * 3 / 4;
			// int height = screenResolution.y;
			if (height < MIN_FRAME_HEIGHT) {
				height = MIN_FRAME_HEIGHT;
			} else if (height > MAX_FRAME_HEIGHT) {
				height = MAX_FRAME_HEIGHT;
			}
			int leftOffset = (screenResolution.x - width) / 2;
			int topOffset = (screenResolution.y - height) / 2 - (screenResolution.y - height) / 7;// 向上移
			framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);
			Log.d(TAG, "Calculated framing rect: " + framingRect);
		}
		return framingRect;
	}

	/**
	 * Like {@link #getFramingRect} but coordinates are in terms of the preview
	 * frame, not UI / screen.
	 */
	public Rect getFramingRectInPreview() {
		if (framingRectInPreview == null) {
			Rect rect = new Rect(getFramingRect());
			Point cameraResolution = configManager.getCameraResolution();
			Point screenResolution = configManager.getScreenResolution();
			// modify here
			// rect.left = rect.left * cameraResolution.x / screenResolution.x;
			// rect.right = rect.right * cameraResolution.x / screenResolution.x;
			// rect.top = rect.top * cameraResolution.y / screenResolution.y;
			// rect.bottom = rect.bottom * cameraResolution.y / screenResolution.y;
			rect.left = rect.left * cameraResolution.y / screenResolution.x;
			rect.right = rect.right * cameraResolution.y / screenResolution.x;
			rect.top = rect.top * cameraResolution.x / screenResolution.y;
			rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y;
			framingRectInPreview = rect;
		}
		return framingRectInPreview;
	}

	/**
	 * Converts the result points from still resolution coordinates to screen
	 * coordinates.
	 *
	 * @param points
	 *            The points returned by the Reader subclass through
	 *            Result.getResultPoints().
	 * @return An array of Points scaled to the size of the framing rect and offset
	 *         appropriately so they can be drawn in screen coordinates.
	 */
	/*
	 * public Point[] convertResultPoints(ResultPoint[] points) { Rect frame =
	 * getFramingRectInPreview(); int count = points.length; Point[] output = new
	 * Point[count]; for (int x = 0; x < count; x++) { output[x] = new Point();
	 * output[x].x = frame.left + (int) (points[x].getX() + 0.5f); output[x].y =
	 * frame.top + (int) (points[x].getY() + 0.5f); } return output; }
	 */

	/**
	 * A factory method to build the appropriate LuminanceSource object based on the
	 * format of the preview buffers, as described by Camera.Parameters.
	 *
	 * @param data
	 *            A preview frame.
	 * @param width
	 *            The width of the image.
	 * @param height
	 *            The height of the image.
	 * @return A PlanarYUVLuminanceSource instance.
	 */
	public PlanarYUVLuminanceSource buildLuminanceSource(byte[] data, int width, int height) {
		Rect rect = getFramingRectInPreview();
		int previewFormat = configManager.getPreviewFormat();
		String previewFormatString = configManager.getPreviewFormatString();
		switch (previewFormat) {
			// This is the standard Android format which all devices are REQUIRED to
			// support.
			// In theory, it's the only one we should ever care about.
			case PixelFormat.YCbCr_420_SP:
				// This format has never been seen in the wild, but is compatible as we only
				// care
				// about the Y channel, so allow it.
			case PixelFormat.YCbCr_422_SP:
				return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top, rect.width(), rect.height());
			default:
				// The Samsung Moment incorrectly uses this variant instead of the 'sp' version.
				// Fortunately, it too has all the Y data up front, so we can read it.
				if ("yuv420p".equals(previewFormatString)) {
					return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top, rect.width(), rect.height());
				}
		}
		throw new IllegalArgumentException("Unsupported picture format: " + previewFormat + '/' + previewFormatString);
	}

	public Context getContext() {
		return context;
	}

}
